well...it never grows in you hair, but if you mean how long can marijuana be detected in the body... its about 3-30days depending on your metabolism
Forever unless you do something to get it out.
About a week
how long will alcohol stay in your hair folical
How long does alochol stay in hair follicles
Not as long as it will stay in short fine hair, but it will stay for awhile.
Drug stay in your hair for months together.
as long as it takes for your hair to grow out
It stays in your hair follicles for life.
Until the hair is cut.
how long does it take for heroine to be negative in a hair strand test
9 months
It will stay for months in your hair and if your really worried shave your hair like Mr. Clean and you'll be golden
Till you cut your hair off
it will stay in there for about 2 years